• The newly installed app detects the other Locus
  
• Confirm selected app directory for the app transfer in the system file manager
• Choose the way of the app data transfer:

• data of one app is moved to the main directory of the other app
• the first app (and other possible apps) loses access to its data (the first app can go on with a new empty database - no maps, no tracks/points etc. - that is created automatically)
• custom sub-directories and external maps are not moved - the updated app doesn't have access to this data

• data of one app is copied to the main directory of the other app
• both apps continue to work independently, each using its own database of tracks, routes and points. The databases are not synced.
• custom sub dirs and external maps are not copied - only the first app keeps access to them

The updated app detects the other Locus Map in the external storage (removable SD card) but it can not migrate its data automatically:
There are a few more steps to do:

• change the location of the main directory of the second Locus Map from the external SD card to the private folder in the internal storage
• update the first Locus Map and continue according to the instructions above